Thursday, July 24, 2014

Thursday, July 24

2:30 p.m.
Theoretical Physics Seminar - Curia II
Speaker: Matthew Reece, Harvard University
Title: Nonthermal SUSY Cosmology, Dark Matter and Indirect Detection

3:30 p.m.

Friday, July 25

3:30 p.m.

4 p.m.
Joint Experimental-Theoretical Physics Seminar - One West
Speaker: Soo-Bong Kim, Seoul National University
Title: Recent Results from RENO

Click here for NALCAL,
a weekly calendar with links to additional information.

Ongoing and upcoming conferences at Fermilab

Weather Sunny

Extended forecast
Weather at Fermilab

Current Flag Status

Flags at full staff

Wilson Hall Cafe

Thursday, July 24

- Breakfast: Canadian bacon, egg and cheese Texas toast
- Breakfast: corned beef hash and eggs
- Carolina pulled pork sandwich
- Smart cuisine: barbecue chicken breast
- Honey baked ham
- Buffalo chicken tender wrap
- Roast beef carvery
- White chicken chili
- Chef's choice soup
- Assorted pizza by the slice

Wilson Hall Cafe menu

Chez Leon

Friday, July 25
- Spinach and blue cheese souffle
- Filet mignon with cabernet sauce
- Golden mashed potatoes with fried onions and bacon
- Broccoli
- Coffee creme brulee

Wednesday, July 30
- Honey ginger grilled salmon
- Coconut rice
- Roasted broccoli
- Tropical cake

Chez Leon menu
Call x3524 to make your reservation.


Fermilab Today

Director's Corner

Frontier Science Result

Physics in a Nutshell

Tip of the Week

User University Profiles

Related content


Fermilab Today
is online at:

Send comments and suggestions to:

Visit the Fermilab
home page

Unsubscribe from Fermilab Today


Fermilab technology available for license: Bed-ridden boredom spurs new invention

Fermilab engineer Jim Hoff recently invented an electronic circuit that can guard against radiation damage. Photo: Hanae Armitage

Fermilab engineer Jim Hoff, PPD, has received patent approval on a very tiny, very clever invention that could have an impact on aerospace, agriculture and medical imaging industries.

Hoff has engineered a widely adaptable latch — an electronic circuit capable of remembering a logical state — that suppresses a commonly destructive circuit error caused by radiation.

There are two radiation-based errors that can damage a circuit: total dose and single-event upset. In the former, the entire circuit is doused in radiation and damaged; in an SEU, a single particle of radiation delivers its energy to the chip and alters a state of memory, which takes the form of 1s and 0s. Altered states of memory equate to an unintentional shift from logical 1 or logical 0 and ultimately lead to loss of data or imaging resolution. Hoff's design is essentially a chip immunization, preemptively guarding against SEUs.

"There are a lot of applications," Hoff said. "Anyone who needs to store data for a length of time and keep it in that same state, uncorrupted — anyone flying in a high-altitude plane, anyone using medical imaging technology — could use this."

Past experimental data showed that, in any given total-ionizing radiation dose, the latch reduces single-event upsets by a factor of about 40. Hoff suspects that the invention's newer configurations will yield at least two orders of magnitude in single-event upset reduction.

The invention is fondly referred to as SEUSS, which stands for single-event upset suppression system. It's relatively inexpensive and designed to integrate easily with a multitude of circuits — all that's needed is a compatible transistor.

Hoff's line of work lies in chip development, and SEUSS is currently used in some Fermilab-developed chips such as FSSR, which is used in projects at Jefferson Lab, and Phoenix, which is used in the Relativistic Heavy Ion Collider at Brookhaven National Laboratory.

The idea of SEUSS was born out of post-knee-surgery, bed-ridden boredom. On strict bed rest, Hoff's mind naturally wandered to engineering.

"As I was lying there, leg in pain, back cramping, I started playing with designs of my most recent project at work," he said. "At one point I stopped and thought, 'Wow, I just made a single-event upset-tolerant SR flip-flop!'"

While this isn't the world's first SEUSS-tolerant latch, Hoff is the first to create a single-event upset suppression system that is also a set-reset flip-flop, meaning it can take the form of almost any latch. As a flip-flop, the adaptability of the latch is enormous and far exceeds that of its pre-existing latch brethren.

"That's what makes this a truly special latch — its incredible versatility," says Hoff.

From a broader vantage point, the invention is exciting for more than just Fermilab employees; it's one of Fermilab's first big efforts in pursuing potential licensees from industry.

Cherri Schmidt, head of Fermilab's Office of Partnerships and Technology Transfer, with the assistance of intern Miguel Marchan, has been developing the marketing plan to reach out to companies who may be interested in licensing the technology for commercial application.

"We're excited about this one because it could really affect a large number of industries and companies," Schmidt said. "That, to me, is what makes this invention so interesting and exciting."

Hanae Armitage

In the News

Fermilab releases Scientific Linux 7.0 Alpha 2

From Softpedia, July 14, 2014

The developers of Scientific Linux 7.0 have moved very fast and, just a week after the first Release Candidate, a new development release has been made available. Given the short development period since the first Alpha, it's actually surprising that the devs managed to get all those changes and improvements in.

"Fermilab's intention is to continue the development and support of Scientific Linux and refine its focus as an operating system for scientific computing. Today we are announcing an alpha release of Scientific Linux 7. We continue to develop a stable process for generating and distributing Scientific Linux, with the intent that Scientific Linux remains the same high quality operating system the community has come to expect."

"The 'everything' dvd image requires a Dual-Layer (DL) compatible drive for both burning and booting off of. The livecd-iso-to-disk utility is able to convert this to USB successfully," reads the official announcement.

Read more

Frontier Science Result: CDF

Searching for boosted tops

This plot shows the mjet1 versus mjet2 distribution for the data taken in this experiment.

At CDF, protons of energy 1 TeV, or 1 trillion electronvolts, collided with antiprotons of equal energy.

In many of these events, we observe a phenomenon called a jet. A jet is a spray of particles all moving in the same direction and typically originating from a practically massless subatomic particle, which is why it is also expected to have a low mass. It is fascinating that in some cases these jets have masses that are a substantial fraction of their energy.

Scientists have studied events in which a very large fraction — at least 40 percent — of the collision energy is transformed into just two such jets. Based on the internal structure of these jets, we have found that they appear mostly to come from very energetic quarks.

There are six different flavors of quarks, with five of the six having masses that are small compared to the masses of the jets we see in these two-jet (or "dijet") events.

If these jets originate from the lighter quarks, then we would expect to see a high occurrence of jets with low masses. The above figure plots the masses of one jet against the other, and indeed we see that most of the events in our sample have two jets where each has a mass between 40 and 60 GeV/c2, or between 50 and 70 proton masses. This amount of mass is consistent with predictions of quantum chromodynamics, the theory describing the strong interaction.

But what if some of these massive two-jet events were really coming from the production of the super-massive top quark, which has a mass of 173.34 ± 0.76 GeV/c2? We then would expect to see a cluster of events in which both jets had masses between about 140 and 200 GeV/c2. Although there are roughly 30 such events in our data, as seen in the figure, it is only slightly more than we might have expected from the very occasional production of two very massive jets from the lighter quarks.

We can use these data to set an upper limit on the rate of top quarks being produced at these very high energies at about 40 femtobarns, or no more often than about one collision in every trillion. Our current understanding of the strong interactions is that the expected rate of top quark production corresponding to two-jet events is about 5 femtobarns.

Learn more

Pekka Sinervo and Andy Beretvas

These CDF physicists contributed to this data analysis. Top row from left: Raz Alon and Ehud Duchovni (Weizmann Institute of Science, Rehovot, Israel). Second row: Gilad Perez (Weizmann Institute of Science, Rehovot, Israel). and Pekka Sinervo (University of Toronto).
Photo of the Day

Lovely and temperate

Blue sky, billowy clouds and a barn in the distance make for a picturesque summer day, as seen in this photo taken near NML. Photo: Jamie Santucci, AD

Vehicles in restricted parking lots from July 25-27 will be towed

English country dancing Sunday at Kuhn Barn - July 27

Final swim lessons registration due July 28

Fermilab prairie plant survey - Aug. 9

Deadline for the University of Chicago tuition remission program - Aug. 18

Call for applications: URA Visiting Scholars Program - apply by Aug. 25

Fermilab Tango Club

Scottish country dancing Tuesday evenings in Ramsey Auditorium

International folk dancing Thursday evenings in Ramsey Auditorium

Outdoor soccer

Fermi Days at Six Flags Great America

Employee Appreciation Day at Hollywood Palms Cinema